A new approach for temperature control of medical air insulation blanket

To meet the technical demands of temperature control in medical air insulation blanket, a closed loop system of temperature control is put forward, in which the hardware circuit is mainly composed of temperature sensor, MCU and RS232 communication module etc. Through changing the work time of the electrically heated wire via controlling the turn-on time of the thyristor by the PWM technique and adaptive fuzzy PID technique, the air temperature from the outlet of the insulation blanket's gasbag is automatically adjusted and controlled. The whole control process is divided into two stages: the duty cycle of the electrically heated wire's work time is set to be 100% at the initial auto adjustment stage, and then is determined by a relevant control variable during the stage of adaptive fuzzy PID algorithm control when the air temperature rises up to a certain range, hence the air temperature is regulated. The MATLAB simulation based on the control method shows that the adaptive fuzzy PID algorithm control is superior to conventional PID control due to the former excellent adaptability, robustness and the steady-state accuracy.